This invention relates generally to bearing housings for rotary bearings and, more particularly, to housings for self-aligning anti-friction ball and roller bearings.
To accommodate misalignment of a shaft mounted within anti-friction bearings, the outer ring of the bearings may be formed with an outer spherically convex surface for mating engagement with a spherically concave surface of a housing in which the bearings are supported. Such bearing housings may be of the pillow block type, having an upper bight portion and a lower portion with outturned apertured mounting feet, or of a flange type configuration.
In some bearing housing applications, such as for example in food processing, bearing housings are continually subjected to corrosive chemicals, extreme changes in temperature, and high pressure steam. Historically, to withstand those conditions, such bearing housings have been made of cast iron and plated with nickel, or cast and machined of stainless steel, resulting in high manufacturing cost.
Even when made of nickel plated iron, bearing housings may rust due to chipping of the nickel plating during installation of the bearing housing or due to peeling or other damage to the nickel plating during repeated exposure to high pressure steam or other adverse conditions. Another problem associated with bearing housings made of nickel plated iron is the cost of proper environmental disposal of manufacturing bi-products.
Pillow blocks and other bearing housings made of glass reinforced nylon or similar polymers have been proposed for some applications. However, although those materials resist corrosion, bearing housings made of those materials do not have adequate stiffness and long term retention torque to prevent spinning of the bearing in the housing. Also, they are not sufficiently resistant to creep, moisture absorption, and thermal deflection to permit their use in the applications described above and are not generally approved for use in food processing.
To provide the spherically concave bore of bearing housings made of iron or steel, machining has been used. Alternatively, two-piece bearing housings made of glass reinforced nylon have been proposed with multiple shell sections that are guided by grooves or dove tails to clamp the bearing in a bearing seat. Molding or casting of the spherically concave bore as a finished one-piece bearing housings made of either iron, steel, or glass reinforced nylon has not been practical.
The foregoing illustrates limitations known to exist in present bearing housings. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one of more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.